Coating and bonding agents of acetoacetates of polyvalent metals,diluents and copolymers of acetoacetic acid esters

ABSTRACT

Coating and bonding agents based on mixtures of acetoacetates of polyvalent metals, diluents, copolymers of polymerizable acetoacetic esters having the general formula WHERE Y is a hydrocarbon radical and R is H or CH3, and acrylic and/or methacrylic esters and/or styrene given hard and clear films which are resistant to weathering and may chemicals.

United States Patent [72] lnventors Matthias Marx Bad Duerkhelm; HermannPankraz I-Iolmann, Frankenthal, Upper Palatlnate; Hans Klug,Lamperthelm, all of Germany [21] Appl. No. 740,104

[22] Filed June 26, 1968 [45] Patented Sept. 21, 1971 [73] AssigneeBadische Anilin-& Soda-Fabrik Aktlengesellschaft Ludwigshafen am Rhine,Germany 32] Priority June 28, 1967 [3 3] Germany [54] COATING ANDBONDING AGENTS 0F ACETOACETATES 0F POLYVALENT METALS, DILUENTS ANDCOPOLYMERS 0F ACETOACETIC ACID ESTERS 4 Claims, No Drawings [52] US. Cl260/63R, 117/124 E, 117/132 C, 1l7/138.8 UA, 117/148,

117/161 UZ, 117/161 UT, 260/29.6 RW, 260/29.6

TA, 260/312 R, 260/3 1.2 N, 260/32.8 R, 260/32.8

N, 260/33.2 R, 260/33.4 R, 260/33.6 UA, 260/63 N, 260/80.5, 260/85.5 ES,260/85.5 XA, 260/86.l

Primary ExaminerWilliam H. Short Assistant ExaminerL. L. Lee

Attorney-Johnson, Root, OKeefe, Keil, Thompson &

Shurtleff ABSTRACT: Coating and bonding agents based on mixtures ofacetoacetates of polyvalent metals, diluents, copolymers ofpolymerizable acetoacetic esters having the general formulaCH3-(I'IJCH,(HIO-YI)('3C=CH;

where Y is a hydrocarbon radical and R is H or CH;,, and acrylic and/ormethacrylic esters and/or styrene given hard and clear films which areresistant to weathering and may chemicals.

COATING AND BONDING AGENTS OF ACE'IOACETATES OF POLYVALENT METALS,DILUENTS AND COPOLYMERS OF ACETOACETIC ACID ESTERS This inventionrelates to coating and bonding agents based on copolymers containingacetoacetate groups.

Surface coating based on mixtures of polymers having chelate-forminggroups, metal chelate compounds and diluents are known from UK Pat.Specs. Nos. 791,325 and 807,198. Copolymers of acryloacetone or vinylsalicylate with other ethylenically unsaturated compounds are used aspolymers capable of forming metal chelates. Examples of metal chelatecompounds used for the prior art coating agents are acetylacetonates ofaluminum, magnesium and zinc. A reaction including cross-linking of thepolymer takes place between the acetylacetonates and the copolymershaving chelate-forming groups during the formation of a film from thesolutions or during heating of the film. Films which are not resistantto chelate-forming solvents such as acetylacetone or ethyl acetoacetateare obtained however by the said prior art methods. Moreover aqueoussolutions of the polymerized chelate-forming binders cannot be used inthe said prior art methods because known chelatizing polymers aresuddenly separated as insoluble precipitates when their solutions arebeing concentrated.

We have now found that coating and bonding agents based on mixtures of(i) polymers of ethylenically unsaturated compounds having acetylacetategroups, (ii) acetoacetates of polyvalent metals, (iii) diluents and ifdesired (iv) one or more additives do not have the said disadvantageswhen they contain, as the polymers having acetylacetate groups,copolymers of (a) 10 to 95 percent of their weight of polymerizedacetoacetic esters having the general formula:

I! o g OR in which Y denotes a hydrocarbon radical having two to tencarbon atoms and R denotes a hydrogen atom or a methyl group, (b) 5 to90 percent of their weight of acrylic and/or methacrylic esters ofalkanols having one to twenty carbon atoms and/or styrene and (c) 0 to30 percent of their weight of one or more ethylenically unsaturatedmonomers.

The acetylacetonates of aluminum, zinc, nickel and beryllium, ormixtures of such acetylacetonates, are of special interest asacetylacetonates of polyvalent metals. Examples of otheracetylacetonates are those of magnesium, zirconium, titanium, cobalt,copper and zinc. These acetylacetonates are known and can be obtained byconventional methods. The acetylacetonates are preferably used in theform of their solutions for the coating and bonding agents. They mayalso be stirred for example in solid form into the solutions of thecopolymers.

Examples of suitable solvents for the coating and bonding agentsaccording to the invention are aromatic hydrocarbons such as benzene,toluene and xylene, ketones such as methyl ethyl ketone, esters ofsaturated carboxylic acids such as ethyl acetate, butyl acetate andmethyl glycol acetate, essential oils such as spirits of turpentine andpine oil, alcohols such as methanol, ethanol, isopropanol, n-butanol,isobutanol and glycol and also glycol ethers, for example the methylether of glycol. In some cases small amounts of volatile solvents,particularly acetone or tetrahydrofuran, are advantageous. Water is alsovery suitable as well as mixtures thereof with water-miscible solvents.These solvent mixtures and water are particularly suitable when thepolymers used for the coating and bonding agents have strongly polargroups, for example carboxylate, ammonium or hydroxy groups.

The polymers having acetylacetate groups contain to 95 percent,preferably 25 to 70 percent, of their weight of polymerized units ofpolymerizable acetoacetic esters of the above-mentioned general formula.These acetoacetic esters may be derived for example from glycol,propanediol-l,2, butanediol-1,4, hexanediol-l,6, octanediol-l,8 orcyclohexanediol-l,4, 2,2-dimethylpropandiol-l,3 and1,4-dimethylolcyclohexane; in each case one hydroxy] group of thesediols is esterfied with acrylic or methacrylic acid and the other withacetoacetic acid. These diesters may be prepared for example by firstreacting diols of the said type with acrylic acid or methacrylic acid toform the hemiester and then converting the free hydroxy] groups intoacetoacetic ester groups with diketene. These reactions can be carriedout by conventional methods. The acetylacetates of glycol monoacrylates,glycol monomethacrylate, butanediol- 1 ,4-monoacrylate andpropanediol-1,2-monoacrylate are examples of particularly suitableacetoacetic acid esters.

The copolymers should also contain 5 to percent of polymerized units ofstyrene and/or acrylic or methacrylic esters of alkanols containing oneto twenty carbon atoms. Acrylic and methacrylic esters of ethanol,n-propanol, isopropanol, n-butanol, tert-butanol and 2ethylhexanol areparticularly suitable acrylic and methacrylic esters of this type.Mixtures of different esters of methacrylic acid or acrylic acid arealso suitable. The content of styrene and/or acrylic or methacrylicesters of the said type in the copolymer is preferably from 20 to 60percent by weight with reference to the copolymer. Copolymers which aresoluble in water are obtained when at least 2 percent by weight ofpolymerizable hydrophilic monomers, for example salts of polymerizableacids such as ammonium acrylate or sodium acrylate, or hydroxyalkylacrylates or ammonium compounds such as the hydrochloride ofdimethylaminoethyl acrylate or methacrylate, are additionally used. Thecopolymers may also contain in addition up to 30 percent of their weightof other ethylenically unsaturated monomers in polymerized form.Examples of such monomers are vinyl esters such asvinyl acetate, vinylpropionate and the vinyl esters of carboxylic acids having a very highdegree of chain branching, for example of carboxylic acids prepared byreaction of olefins with carbon monoxide and water with presence ofsulfuric acid, N-methylolacrylamide and N-methylolmethacrylamide andtheir ethers with alkanols containing one to eight carbon atoms, forexample the n-butyl ether of N-methylolmethacrylamide, and polymerizableacids, such as acrylic acid and methacrylic acid and their salts, amidesand B-hydroxyalkyl esters such as B-hydroxyethyl acrylate,acrylonitrile, methacrylonitrile and also vinyl halides, such as vinylchloride and vinylidene chloride.

The polymers having acetylacetate groups may be prepared bypolymerization of the monomers by conventional methods usingconventional polymerization catalysts. The polymerization is preferablycarried out using free-radical-fonning catalysts in solution or inemulsion. Conventional emulsifiers and/or protective colloids may beused when the copolymers are prepared in aqueous emulsion. The solventsmentioned above may be used as well as water when the polymers areprepared in solution. A preferred method of preparation is precipitationpolymerization.

In some cases it may be advantageous to use (instead of polymerizableacetoacetic esters) appropriate monoesters of acrylic or methacrylicacid with the above-mentioned alkanediols in the production of thepolymers having acetylacetate groups and to react with diketene theresultant copolymers which have free hydroxyl groups in side chains.Such reactions may be carried out for example according to thedescription given in German Pat. Spec. No. 940,680.

The amount of copolymer having acetylacetate groups and of theacetoacetate of a polyvalent metal in the coating or bonding agent maybe varied within wide limits. Good results are achieved when for eachtwo acetylacetate groups of the copolymer in the mixture, one atom of adivalent metal is present in the form of its acetylacetonate. Whenacetylacetonates of trivalent metals are used, particularly good resultsare obtained by providing three acetylacetate groups of the copolymerfor each metal atom. In general 1 to 3, or 2 to 4, or 3 to 5acetylacetate groups of the copolymer should be provided for 1 atom ofthe metal used as acetoacetate in the coating or bonding agent,depending on whether the metal used is divalent, trivalent ortetravalent.

Solutions or dispersions of copolymers having acetylacetate groups aremixed preferably with solutions of the metal acetoacetates in thepreparation of the coating or bonding agents. The amount of solvent ordiluent may be varied within limits. The mixtures generally contain 20to 70 percent by weight of polymers having acetylacetate groups, withreference to the mixture of these polymers, the acetoacetates of heavymetals and the solvents or diluents. The mixtures may also containconventional additives such as plasticizers, pigments, flow improvers,other binders such as phenoplast resins, aminoplast resins, phthalateresins, oil-modified phthalate resins, alkyd resins, epoxy resins,acrylate resins, cellulose derivatives and/or colophony or derivativesof the same.

The coating or bonding agents may be applied to the substrate, forexample to. a metal, in the conventional ways. They may be allowed todry out at room temperature or they may be baked at elevatedtemperature, for example at temperatures up to 200 C. Clear films arethus obtained which are hard and weather resistant and also resistant tomost chemical reagents. The films are insoluble in chelate-formingsolvents such as acetylacetone and ethyl acetoacetate. Autoxidativecross-linking of the polymer may take place in the coating and bondingagents according to this invention under the action of atmosphericoxygen or other agents supplying oxygen. This autoxidation can beaccelerated by adding a small amount of a heavy metal compound, forexample a compound of iron, cobalt, lead or manganese such as cobaltnaphthenate, cobalt octoate, cobalt acetate, cobalt acetate bromide,iron naphthenate and/or cobalt-lead-manganese octoate. They generallyconsiderably improve the resistance of the coatings and impregnations tochemical reagents and their mechanical properties.

The new coating and bonding agents may be used to prepare coatings byspraying, brushing or dipping methods and may be applied to metal, wood,glass, porcelain and plastics. They are moreover suitable for bondingtextiles and nonwovens and also as bonding agents in the production oflaminates and laminated articles. Bonding in this specification isintended to include use of the bonding agents for the production ofbonded nonwovens.

The invention is illustrated by the following Examples. The parts andpercentages specified in the following examples are by weight.

EXAMPLE 1 13 parts of a 50 percent solution of a copolymer of 50 partsof butanediol-1,4 acrylate acetylacetate, 45 parts of methylmethacrylate and 5 parts of acrylic acid in butyl glycol has added to it2 parts of concentrated aqueous ammonia solution, 30 parts of water andparts of a 10 percent solution of aluminum triacetylacetonate in acetoneand the whole is stirred until a homogeneous solution has been formed.

A film of the solution is allowed to dry out on a sheet of glass at C.After the solvent has evaporated, a clear hard coating has formed whichis insoluble in 10 percent aqueous caustic soda solution and inconcentrated aqueous ammonia solution. After having been kept for a fewdays, the coating is insoluble in boiling ethyl acetate.

EXAMPLE 2 3 parts of aluminum triacetylacetonate is dissolved cold in 50parts of a 60 percent solution of a copolymer of parts of butanediol-L4acetylacetate, 45.5parts of methyl methacrylate and 4.5parts of acrylicacid in butyl diglycol (viscosity measured in a DIN beaker having a 6mm. nozzle 180 seconds). Then 2 parts of a 20 percent solution of cobaltnaphthenate in ethyl glycol, 10 parts of concentrated aqueous ammoniasolution, 45 parts of water and 5 parts of turpentine are stirred inconsecutively.

The coating agent obtained dries on wood, expanded polystyrene, asbestoscement, metal, glass and the like to give clear adherent scuffresistant, highly elastic films which are resistant to chemicalreagents.

We claim:

1. A coating or bonding agent comprising A. a copolymer consistingessentially of a. 10 to 95 percent of its weight of a polymerizedacetoacetic ester having the general formula:

in which Y denotes a hydrocarbon radical having two to ten carbon atomsand R denotes a hydrogen atom or the methyl group;

b. 5 to percent of its weight of polymerized units of an acrylic esteror methacrylic ester of an alkanol having one to eight carbon atoms,styrene, and mixtures thereof; and

c. 0 to 30 percent of its weight of polymerized units of one or moreother ethylenically unsaturated monomers selected from the groupconsisting of a vinyl ester of a monocarboxylic acid, acrylamide,methacrylamide, N- methylolacrylamide, N-methylolmethacrylamide, ethersof N-methylolacrylamide with alkanols containing one to eight carbonatoms, ethers of N-methylolmethacrylamide with alkanols containing oneto eight carbon atoms, ,B-hydroxyalkylacrylate,,B-hydroxyalkylimethacrylate, acrylic acid, methacrylic acid, ammoniumacryiate, ammonium methacrylate, sodium acrylate, sodium methacrylate,methacrylonitrile, vinylchloride and vinylidene chloride;

B. an acetoacetate of a polyvalent metal selected from the groupconsisting of aluminum, zinc, nickel, beryllium, magnesium, zirconium,titanium, cobalt and copper; and

C. an inert diluent.

2. A coating or bonding agent as claimed in claim 1 wherein the amountof component (a) is 25 to 70 percent.

3. A coating or bonding agent as claimed in claim 1 wherein the amountof component (b) is 20 to 60 percent.

4. A coating or bonding agent as claimed in claim 1 which contains inthe copolymer at least 2 percent by weight of polymerized units of apolymerizable hydrophilic monomer selected from the group consisting ofammonium acrylate and ammonium methacrylate.

2. A coating or bonding agent as claimed in claim 1 wherein the amountof component (a) is 25 to 70 percent.
 3. A coating or bonding agent asclaimed in claim 1 wherein the amount of component (b) is 20 to 60percent.
 4. A coating or bonding agent as claimed in claim 1 whichcontains in the copolymer at least 2 percent by weight of polymerizedunits of a polymerizable hydrophilic monomer selected from the groupconsisting of ammonium acrylate and ammonium methacrylate.